f the advocacy in ‘the leaflet of the 
Iphate of ammonia to the wheat crop 
mn months. In view of this criticism 
ght desirable to embody in the new 
justification of the recommendation. 
at on the average of years, if a 
exceeding, say, # cwt. sulphate of 
to be used, spring dressing may be ex- 
_ pected to: pay better than autumn dressing. It is 
: argued, however, that with wheat high in price much 
_ heavier dressings can be profitably applied, that these 
_ must in any ¢ase*be given in two or more instalments, 
and that the best result may be expected from them if a 
_ portion be applied in the autumn and the balance in 
the spring. It is further urged that the common fear 
_ of loss of soluble salts by leaching throughout the 
winter is lixgely groundless in the case of sulphate 
~ of ammonia, since the ammonia is firmly retained by 
; the soil and is only readily removed by water after 
application 
during the 
it has beer 
ae 
conversion to the form of nitrate. Such nitrification 
being the outcome of bacterial activity, little 
_ change of ammonia is likely to take place at the low 
_ temperatures obtaining in the soil during the winter 
months. ; 
THE at! of teachers of geography should be 
_ directed to the fine illustrations which are a feature of 
the National Geographic Magazine, published in 
_ Washington. The magazine is ostensibly a popular 
_ publication, and fulfils its object of increasing and 
diffusing geographical knowledge. The issue for 
August, Bo Nga xxx., No. 2), contains, amon 
others, articles on Sardinia, Argentine and Chile, an 
San Domingo and Hayti. The chief feature of each 
article is the illustrations, many of which have con- 
siderable geographical value, and all of which are 
admirably rep: sows It is not easy to get illustra- 
tions of the negro republic of Hayti, and those in this 
magazine give a vivid impression of the island and its 
chief towns. The people of the countries concerned 
are well illustrated in all the articles. 
iy! 
Ox the Monthly Meteorological Chart of the North 
Atlantic and Mediterranean for October there appears the 
usual inset map of “phenomenal drifts and-heights ” 
of North Atlantic ice. We notice in this map a 
record, which has appeared in many previous issues, 
of rea: ap an iceberg, recorded near the island 
of Colonsay, off the Firth of Lorne, in the west of 
Scotland. It was sighted by fishermen in July, 1902. 
It is a little difficult to credit this remarkable occur- 
rence, and if the fishermen were not mistaken the 
iceberg would surely have been seen by other observers, 
but the chart makes no mention of this. There are 
conditions of sea and weather in which ice can easily 
be imagined, and this suggests one of those cases. 
Unless the record is established beyond all doubt, it 
would be well to query this occurrence or to remove 
its indication from the chart. 
We learn from the Geographical Journal for Sep- 
tember that the Arkhangel Society for the study of the 
Russian North is taking steps to obtain information 
as to the fate of the two Russian polar expeditions, of 
which there has been no news for several years. 
Rusanoff's expedition in the Hercules visited Spits- 
bergen in the summer of 1912, and was last heard of 
. the same year in Novaya Zemlya, on its way through 
the Matochin Shar to the Kara Sea. Ice conditions 
were exceptionally severe in Arctic seas in 1912. The 
other expedition, in the St. Anna, passed through 
Yugor Strait in September, 1912, with the intention 
of making the north-east passage. It was afterwards 
Jearnt that the St. Anna was abandoned in April, 
1914, in 83° N., 63° E. Several Russian search expe- 
ditions have failed to reveal any further news. The 
% NO. 2449, VOL. 98] 
NATURE 
97 
Arkhangel Society is raising a fund of 2500l. to be 
spent during the next three years in prizes for in- 
formation throwing any light on the fate of the ex- 
plorers. It is almost impossible that there can now 
be any survivors. 
Tue Philippine Journal of Science for January con- 
tains an interesting paper by G. W. Heise on the 
water supply of the city of Manila. The water is 
derived from the upper reaches of the Mariquina River, 
and the only physical purification it receives is storage 
in a reservoir for about three and a half days, which 
reduces the bacteriological count by about go per cent. 
The water is then treated with chloride of lime in 
doses varying from o-5 to 0-75 part of available 
chlorine per million parts of water. This treatment 
appears to be still in a more or less experimental. 
stage, and while, on the face of it, the sterilisation 
does not quite come up to expectations, some interest- 
ing results were obtained. Perhaps the most note- 
worthy of these is that the benefit derived from in- 
creasing the dose from o-5 part of available chlorine: 
per million to 0-625 part is very much greater than 
that derived by a further increase from the latter 
figure to 0-75 part. These results are chiefly judged 
by bacteriological counts made on the water before- 
treatment and three-quarters of an hour after 
treatment. Possibly, if the results were judged on 
tests for B. coli done on various volumes of water 
(say 100 €.c., 10 C.C., I C:C., OI c.c., etc.) instead of 
only on 2 ¢.c., and after longer contact (say three or 
four hours) of the water with the germicide, they 
would then wear a more favourable aspect, and at 
‘the same time give a truer estimate of the effect of 
the treatment. 
Unpber the title ** Mathematical Portraits and Pages” 
Messrs. Ginn and Co. have issued an attractive illus- 
trated pamphlet of about twenty pages, drawn up by 
Prof. David Eugene Smith. The contents include 
reproductions of portraits of Newton, Isaac Barrow, 
John Wallis, Nicholas Saunderson, and Brook Taylor 
(of Taylor’s theorem), also facsimiles of pages of. 
“The Craft of Nombryng,” Tonstall’s ‘‘De Arte 
svppvtandi,"’ Recorde’s **Grovnd of Artes" and his 
‘“Whetstone of Witte,” and the title-page of Digges. 
and Son’s ‘Stratioticos.”’ : 
WHILE the late Captain Ferber was probably the 
first to consider lateral stability in applying the equa-- 
tions of rigid dynamics to the motions of aeroplanes, 
he unfortunately assumed that an aeroplane could be 
replaced by a system of three mutually orthogonal 
plane surface-elements, and it is greatly to be feared 
that the accident in which he lost his life may have 
arisen through the consequent misunderstanding of 
the problem. In the Téhoku Mathematical Journal, 
ix., 4, Mr. Selig Brodetsky has now taken up the 
question as to how far it is possible, even on the’ 
simple ‘‘ sine-law”’ hypothesis, to replace an aeroplane 
by three or more equivalent surfaces in three planes 
at right angles. The investigation leads to some ex- 
ceedingly heavy algebra, which Mr. Brodetsky may 
claim to have worked out to the bitter end, with, 
briefly speaking, the following results :—(1) Except in 
the case of small divergences from a. state of steady 
motion no such representation is possible; (2) in the 
case of small oscillations three planes are insufficient, 
but it is possible to represent the system by six sur- 
face-elements, namely, two in each of the three ‘co- 
ordinate planes. 
Wuite the claims of Napier as the discoverer of 
logarithms have received ample recognition in 
connection with the tercentenary celebration in 
1914, it is interesting to notice that a system 
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